阅读说明：本技术 具有页张传送带的印刷机 (Printing machine with sheet transport belt ) 是由 M·默林格 于 2019-05-30 设计创作，主要内容包括：本发明涉及一种印刷机,包括用于输送页张(1)的第一传送带(4)和连接在后的第二传送带(5)和位于其间的用于页张(1)的引导元件(11)。设有喷吹装置(13)用于在从所述第一传送带(4)到所述引导元件(11)的过渡区域中提升各页张(1)的前棱边(15)。(The invention relates to a printing press comprising a first conveyor belt (4) for conveying a sheet (1), a second conveyor belt (5) connected downstream and a guide element (11) for the sheet (1) located therebetween. A blowing device (13) is provided for lifting the leading edge (15) of each sheet (1) in the transition region from the first conveyor belt (4) to the guide element (11).)

1. Printing press comprising a first conveyor belt (4) for conveying a sheet (1) and a second conveyor belt (5) following the first conveyor belt and comprising a guide element (11) for the sheet (1) between the first and second conveyor belts,

it is characterized in that the preparation method is characterized in that,

a blowing device (13) is provided for raising the leading edge (15) of the respective sheet (1) in the transition region from the first conveyor belt (4) to the guide element (11).

2. The printing press as set forth in claim 1,

it is characterized in that the preparation method is characterized in that,

the blowing device (13) is arranged upstream of the guide element (11) as viewed in the transport direction (T) of the sheet (1).

3. A printing press according to claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

the blowing device (13) is arranged inside the path of revolution of the first conveyor belt (4).

4. A printing press according to any one of claims 1 to 3,

it is characterized in that the preparation method is characterized in that,

the first conveyor belt (4) has perforations (6) and

the blowing device (13) blows through the perforations (6) toward the respective sheet (1).

5. A printing press according to any one of claims 1 to 4,

it is characterized in that the preparation method is characterized in that,

a valve (14) is provided for activating the blowing device (13) at the transport cycle of the sheet (1).

6. A printing press according to claim 5, wherein,

it is characterized in that the preparation method is characterized in that,

the valve (14) is a rotary valve.

7. A printing press according to any one of claims 1 to 6,

it is characterized in that the preparation method is characterized in that,

at least one printing head (3) for inkjet printing is provided, which is directed towards the first conveyor belt (4).

8. A printing press according to any one of claims 1 to 7,

it is characterized in that the preparation method is characterized in that,

the guide element (11) is a guide plate or has a guide plate.

9. A printing press according to any one of claims 1 to 8,

it is characterized in that the preparation method is characterized in that,

the first transfer element (4) is a vacuum conveyor belt.

10. Printing press according to one of claims 1 to 9,

it is characterized in that the preparation method is characterized in that,

the second conveyor belt (5) is a vacuum conveyor belt.

Technical Field

The invention relates to a printing press comprising a first conveyor belt for conveying sheets and a second conveyor belt following the first conveyor belt, and a guide element for the sheets located between the first and second conveyor belts.

Background

DE 102005055364 a1 describes a printing press in which transport modules with suction belts are provided, a guide consisting of two rollers is arranged between adjacent transport modules, it being provided that when the leading edge of a sheet reaches the gap between the two rollers, the sheet sticks (ü bersteht) above the first suction belt.

Disclosure of Invention

The aim of the invention is to provide a printing press suitable for non-stationary (simple) sheets.

The object is achieved by a printing press comprising a first conveyor belt for conveying sheets and a second conveyor belt connected downstream of the first conveyor belt, and a guide element for the sheets located therebetween, characterized in that a blowing device is provided for raising the leading edge of each sheet in the transition region from the first conveyor belt to the guide element.

The advantage of the printing press according to the invention is that the collision of the leading edge with the guide element is reliably avoided by the blowing device.

The printing press according to the invention is therefore suitable not only for stable sheets but also for unstable sheets.

There are different feasible improvements.

The blowing device can be arranged (as viewed in the transport direction of the sheet) in front of the guide element.

The blowing device can be arranged within the swivel track of the first conveyor belt.

The first conveyor belt may have perforations, and the blowing device may blow through the perforations towards the respective sheet.

A valve can be provided for activating the blowing device in the transport cycle (Transporttakt) of the sheet.

The valve may be a rotary valve. The rotary valve may be driven by a servo motor. The rotary valve can be non-uniform with constant speed of the first and second conveyor belts

The speed is driven.

The printer may be a digital printer (particularly for inkjet printing).

The guide element may be a guide plate or have a guide plate.

The first conveyor belt and/or the second conveyor belt may be a vacuum (conveyor) belt.

Drawings

Further developments emerge from the following description of embodiments and the accompanying drawings, in which:

FIG. 1 a: a side view of a sheet transport apparatus having a first conveyor and a second conveyor during a first motion phase in which a sheet is transported from the first conveyor to a guide element;

FIG. 1 b: a top view of the sheet transport device in the first movement phase in fig. 1 a;

FIG. 2 a: a sheet conveying device in a following second movement phase, in which the sheet conveyed by the first conveyor belt is lifted pneumatically above the guide element by the blowing device;

FIG. 2 b: a top view of the sheet transport device in the second movement phase in fig. 2 a;

FIG. 3 a: a sheet transport device in a third movement phase, in which a front section of the sheet is already guided by the guide element and a rear section is still transported by the first conveyor belt;

FIG. 3 b: a top view of the sheet transport device in the third movement phase in fig. 3 a; and

FIG. 4: an overall view of an inkjet printer including the sheet transport device in fig. 1a to 3 b.

Detailed Description

Fig. 4 shows a digital printing machine, in which a sheet 1 is transported past a print head 3 for ink jet printing by means of a belt conveyor 2 as a sheet transport device.

In fig. 1a to 3b, the belt conveyor 2 comprises a first conveyor belt 4 and a second conveyor belt 5 following the first conveyor belt 4 in the conveying direction T. The two conveyor belts 4,5 are suction or vacuum belts and have perforations 6, through which perforations 6 suction boxes 7 hold the sheet 1 pneumatically on the conveyor belt 4 (or 5). Each adsorption tank 7 has an adsorption air interface and is attached by means of said adsorption air interface to an adsorption air generator S symbolically indicated by an arrow. Each conveyor belt 4,5 has a width a which corresponds at least to the width of the largest processable format of the sheet 1. The widths a of the two conveyor belts 4,5 can be identical to one another or different from one another. Each conveyor belt 4,5 runs by means of at least two rollers 8,9, one of these rollers 8,9 being a drive roller and the other a diverting roller. Only the rollers 8 of the first conveyor belt 4 which are forward in the transport direction T and the rear rollers 9 of the second conveyor belt 5 are shown in the figure; the two further rollers of the conveyor belts 4,5 are not shown together.

The upper return sections of the two belts 4,5 lie in the same plane (i.e. coplanar), the lower return sections can likewise lie coplanar (example in fig. 4) or offset from one another in the vertical direction, i.e. plane-parallel (fig. 1a), a wedge-shaped intermediate space 10 is present between the front roller 8 of the first belt 4 and the rear roller 9 of the second belt 5, said intermediate space 10 being bridged by a guide element 11 for the sheet 1 (ü berbr ü ckt), the guide element 11 can be a guide plate or guide plate (fig. 1a), or an air box with a cover plate as guide plate (fig. 4), in both variants the guide element 11 has a flat guide surface which is plane-parallel to the outer surface of these belts 4,5 which carries the sheet 1, the rear edge 12 of the guide element 11 lies above the outer surface of the return sections of the first belt 4, the rear edge 12 of the guide element 11, viewed in the conveying direction T, lies at least at the level of the axis of rotation R of the front roller 8, or even before the axis of rotation (R position as shown in the figure).

The blowing device 13 is arranged inside the revolving track of the first conveyor belt 4 and between the suction box 7 and the front roller 8. The blowing device 13 extends over the entire width of the sheet 1 and can be configured as a blowing tube or blowing bar. The blowing device 13 with its projecting blowing slot or, alternatively, with its arrangement of blowing openings 16, is directed toward the inner surface of the feed loop of the first conveyor belt 4 and can rest with said blowing slot or blowing opening 16 on this inner surface. The blowing device 13 has a blowing direction which is inclined at a preferably acute angle α relative to the transport direction T, wherein a component of the blowing direction is directed along the transport direction T.

The blowing device 13 is connected to a blowing air generator B via a valve 14. The valve 14 is controlled or designed in such a way that the valve 14 causes the blowing device 13 to release blowing air in a periodic manner at the transport cycle of the sheet 1. The valve 14 may be a magnetic valve or other switching valve, but is preferably a rotary valve (as shown). The blowing device 13 blows through the perforation 6 toward the front edge 15 of the sheet 1, so that the front edge 15 of the sheet 1 is lifted briefly to a vertical height (Niveau) above the rear edge 12 of the guide element 11, as shown in fig. 2 a. In this case, only the front edge 15 of the sheet 1 is lifted from the first conveyor belt 4 by the blowing air release, while the rear section of the sheet 1 remains flat on the first conveyor belt 4. By lifting the front edge of the sheet, a collision of the front edge 15 of the sheet 1 running in the transport direction T with the rear edge 12 of the guide element 11 is avoided, and a lossless displacement of the sheet 1 onto the guide element 11 is ensured without bending or the like, as shown in fig. 3 a.

The guide element 11 has a length L to be measured in the transport direction T, which is smaller than the length of each processable format (i.e. including the smallest format) of the sheet 1. This ensures that the sheet 1 sliding on the guide element 11 is reliably held at any time by the at least one conveyor belt 4 (or 5) and cannot move uncontrollably. The length L is measured in such a way that the sheet 1 sliding on the guide element 11 comes into contact with both conveyors 4,5 at the same time as the sheet 1 is transferred from the first conveyor 4 to the second conveyor 5, and is sucked in by these conveyors 4, 5. The sheet 1 can be slid on the guide element 11 either with the sheet 1 coming into direct physical contact with the guide element 11 or, if the guide element 11 has an air-jet nozzle for carrying the sheet 1, can be suspended on a blowing air cushion (blowpit).

List of reference numerals

1 sheet of paper

2 Belt conveyor

3 printing head

4 first conveyor belt

5 second conveyor belt

6 perforation

7 adsorption tank

8 front roller

9 rear roller

10 intermediate space

11 guide element

12 (of the guide element 11) rear edge

13 blowing device

14 valve

15 (of sheet 1) front edge

16 blowing opening

Width A

B blowing air generator

Length of L

R axis of rotation

S-adsorption air generator

T direction of conveyance

Angle alpha